As a production technology for a 2-alkyl-4-hydroxymethylimidazole compound, the U.S. Pat. No. 4107308 describes a process comprising reacting butyronitrile with gaseous hydrogen chloride in a lower alkanol solvent to prepare an iminoether compound, reacting this intermediate compound with gaseous ammonia to give butyramidine hydrochloride and further reacting this butyramidine hydrochloride with liquid ammonia in the presence of 1,3-dihydroxyacetone dimer, which process is claimed to give the desired compound in a yield of 58%. However, because it involves the use of hydrogen chloride gas and ammonia gas, this method requires special equipment and entails various problems such as corrosion and pollution, thus being disadvantageous for commercial purposes.
Under the circumstances the inventors of the present invention explored in earnest to develop a method for producing the object compound in good yield using simple equipment and found that the above objective can be realized by reacting a monoaldehyde with ammonia in the first place and, then, introducing hydroxymethylglyoxal into the system for further reaction. The present invention has been developed on the basis of the above finding.